Selection of alternate sources for audio broadcast signals responsive to embedded source identification information

ABSTRACT

An apparatus, program product, and method utilize embedded source identity information within an audio broadcast signal to facilitate the reception of the audio broadcast signal from an alternate source. Such embedded information may be used, for example, to facilitate the automated selection of an alternate source of an audio broadcast signal, e.g., in response to poor reception of the primary source of the audio broadcast signal, so that a listener is less likely to miss any portion of an audio broadcast. In one particular implementation, an audio broadcast signal is a radio signal broadcast by a radio station, whereby suitable alternate sources might include another radio station that broadcasts the audio broadcast signal over a different frequency, a transmission device accessible over a telephone network, or a transmission device accessible over a computer network such as the Internet.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.09/578,172, filed on May 24, 2000 by Cary Lee Bates et al., entitled“SELECTION OF ALTERNATE SOURCES FOR AUDIO BROADCAST SIGNALS RESPONSIVETO EMBEDDED SOURCE IDENTIFICATION INFORMATION,” which application isincorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The invention is generally related to the transmission and reception ofaudio broadcasts, e.g., from radio stations and the like.

BACKGROUND OF THE INVENTION

Radio has been an important part of our culture for many years. Despitecompetition from relatively newer broadcast media such as television andthe Internet, many people still find radio to be an important source ofnews, information, and entertainment. Radio has also significantlyadvanced since the days of analog AM and FM broadcasts. For example,radio broadcasts are now capable of being broadcast in a digital format,typically using a packet-based communication medium, and often providingbetter sound quality than with older analog technologies. Digital radiobroadcasts are also capable of transmitting additional information tolisteners, e.g., station call letters, program information, etc.

One continually strong market for radio stations has been listeners inautomobiles, particularly due to the fact that visual informationavailable from television and the Internet is not compatible withkeeping one's eyes on the road. Mobile radio receivers commonly known ascar radios or car stereos have long been provided as standard equipmentin automobiles and other vehicles.

Mobile radio receivers have always suffered from the problem of varyingsignal strengths of audio broadcast signals such as radio broadcasts.Radio stations are capable of transmitting over only a certaingeographical area, so the farther a receiver gets from a radiotransmitter, the weaker the signal, and the poorer the reception by thereceiver. Topographical factors such as buildings, tunnels, mountains,etc. can also affect signal strength. Thus, as a listener of aparticular radio station rides along in an automobile, it is notuncommon for the reception of the audio broadcast signal to continuallyincrease and decrease in quality. Furthermore, for travelers that aremerely passing through a geographical area, such travelers will ofteneventually lose reception as they get farther away from the radiostation.

More often than not, the signal strength of an audio broadcast signalwill weaken at the most inopportune times, such as the last inning of abaseball game, during a news conference, during a breaking weatherreport, during a heated discussion on talk radio, etc. Missing out on aninteresting broadcast can be significantly frustrating to listeners, sothe risk of losing reception of an audio broadcast signal has alwaysbeen considered to be a significant drawback of radio.

Outside of the knowledge of many listeners, however, is the fact thatalternate sources of an audio broadcast signal may exist. For example,FCC regulations often limit the transmission power of radio stations incertain areas, requiring that radio stations broadcast over multiplecarrier frequencies from geographically dispersed transmitters toadequately cover a particular listening area. In addition, many audiobroadcast signals are now available on the Internet, and are capable ofbeing accessed by suitable streaming programs executed by computers.When a listener is unaware of an alternate source of an audio broadcastsignal, the listener is required to suffer through poor reception (ifanalog) or intermittent reception (if digital), or to manually searchfor other radio stations that may contain the desired information. Andeven if a listener is aware of a particular alternate source for anaudio broadcast signal, the user is still required to manually interactwith a radio receiver to select the alternate source.

Therefore, a significant need continues to exist in the art for a mannerof alleviating the frustration associated with weak or lost reception ofaudio broadcast signals. In particular, a significant need continues toexist for a manner of facilitating the identification and reception ofaudio broadcast signals from alternate sources.

SUMMARY OF THE INVENTION

The invention addresses these and other problems associated with theprior art by providing an apparatus, program product, and method thatutilize embedded source identity information within an audio broadcastsignal to facilitate the reception of the audio broadcast signal from analternate source. While the invention has a multitude of other uses thatwill become more apparent below, embedded source identity informationmay be used to facilitate the automated selection of an alternatesource, e.g., in response to poor reception of the primary source of theaudio broadcast signal, so that a listener is less likely to missinteresting portions of an audio broadcast.

Any number of different types of alternate sources may be identified byembedded source identity information consistent with the invention. Forexample, particularly where the audio broadcast signal is a radiobroadcast from a radio station, embedded source identity information mayidentify another radio station that broadcasts the audio broadcastsignal over a different frequency. Embedded source identity informationmay also be used to identify a telephone number that a listener may callto continue listening to the audio broadcast. Furthermore, embeddedsource identity information may be used to identify a network address(e.g., a URL) that a listener may be connected to over a computernetwork. It will be appreciated by those of ordinary skill in the arthaving the benefit of the instant disclosure that other alternatesources may be identified by embedded source identity information, andthus the invention is not limited to the particular types of alternatesources described herein.

It will also be appreciated that both the reception and the transmissionof an audio broadcast may accommodate the use of embedded sourceidentity information consistent with the invention.

From the standpoint of reception, an audio broadcast may be received ina manner consistent with the invention by receiving an audio broadcastsignal from a first source, detecting a source identifier in the audiobroadcast signal that identifies an alternate source for the audiobroadcast signal, and receiving the audio broadcast signal from thealternate source identified by the source identifier.

From the standpoint of transmission, an audio signal may be transmittedin a manner consistent with the invention by embedding a sourceidentifier within an audio signal, and broadcasting the audio signalwith the source identifier embedded therein.

These and other advantages and features, which characterize theinvention, are set forth in the claims annexed hereto and forming afurther part hereof. However, for a better understanding of theinvention, and of the advantages and objectives attained through itsuse, reference should be made to the Drawings, and to the accompanyingdescriptive matter, in which there is described exemplary embodiments ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a digital radio receiver consistent withthe invention.

FIG. 2 illustrates an exemplary display panel for the digital radioreceiver of FIG. 1, with an alternate source selection screen displayedthereon.

FIG. 3 is a flowchart illustrating the program flow of a main routineexecuted by the digital radio receiver of FIG. 1.

FIG. 4 is a flowchart illustrating the program flow of the packetreceiver task referenced in FIG. 3.

FIG. 5 is a flowchart illustrating the program flow of the monitor taskreferenced in FIG. 3.

FIG. 6 is a flowchart illustrating the program flow of the use alternatesource routine referenced in FIG. 5.

FIG. 7 is a block diagram of a digital radio transmission systemconsistent with the invention.

DETAILED DESCRIPTION

The discussion hereinafter will focus on a specific implementation ofthe invention in the field of digital radio broadcasting, where an audiobroadcast signal is transmitted in the form of a digital data streamincorporating streamed data packets carrying audio informationrepresentative of an audio broadcast. Consistent with the invention, oneor more alternate sources of an audio broadcast are identified withinthe digital data stream through the use of source identity packetsembedded periodically within the digital data stream. However, it willbe appreciated by one of ordinary skill in the art having the benefit ofthe instant disclosure that certain aspects of the invention will haveapplicability in other applications where audio signals may bebroadcasted, e.g., analog radio broadcasts, etc. Thus, the invention isnot limited to the specific implementations discussed herein.

Turning now to the Drawings, wherein like numbers denote like partsthroughout the several views, FIG. 1 illustrates a specificimplementation of the invention in a digital radio receiver 10, e.g.,suitable for use in a mobile application (as with a car stereo) or astationary application (as with a home stereo). Receiver 10 includes acentral processing unit (CPU) 12 interfaced with a memory 14, withinwhich resides a control program 16 that is executed by the CPU toimplement the functionality described herein, as well as otherfunctionality of a digital radio receiver as is known in the art. Inthis context, CPU 12, memory 14, and control program 16 function as acontroller for the digital radio receiver. In other environments,however, hardwired logic may be used in lieu of a stored program andprocessor, and thus, the invention is not limited to the particularimplementation described herein.

Receiver 10 may be implemented using practically any type of computer,computer system or other programmable electronic device. The CPU 12thereof may include one or more processors (e.g., microprocessors ormicrocontrollers), and the memory may represent volatile or non-volatilesolid state memories, magnetic storage media, optical storage media, orcombinations of the same, as well as any supplemental levels of memory,e.g., cache memories, backup memories (e.g., programmable or flashmemories), read-only memories, etc. In addition, the memory may beconsidered to include memory storage physically located elsewhere in adigital processing system, e.g., any cache memory in a processor, aswell as any storage capacity used as a virtual memory, e.g., as storedon a mass storage device or on another device coupled over a networkinterconnection.

Receiver 10 typically operates under the control of an operating system,and executes various computer software applications, components,programs, objects, modules, etc. (e.g., control program 16, amongothers). Moreover, various applications, components, programs, objects,modules, etc. may also execute on one or more processors in anothercomputer or other device coupled to such receiver via networkedinterconnections, e.g., in a distributed or client-server computingenvironment, whereby the processing required to implement the functionsof a computer program may be allocated to multiple computers over anetwork.

In general, the routines executed to implement the embodiments of theinvention, whether implemented as part of an operating system or aspecific application, component, program, object, module or sequence ofinstructions will be referred to herein as “computer programs”. Thecomputer programs typically comprise instructions that are resident atvarious times in various memory and storage devices in a computer, andthat, when read and executed by one or more processors in a computer,cause that computer to perform the steps necessary to execute steps orelements embodying the various aspects of the invention. Moreover, whilethe invention has and hereinafter will be described in the context offully functioning computers and computer systems, those skilled in theart will appreciate that the various embodiments of the invention arecapable of being distributed as a program product in a variety of forms,and that the invention applies equally regardless of the particular typeof signal bearing media used to actually carry out the distribution.Examples of signal bearing media include but are not limited torecordable type media such as volatile and non-volatile memory devices,floppy and other removable disks, hard disk drives, optical disks (e.g.,CD-ROM's, DVD's, etc.), among others, and transmission type media suchas digital and analog communication links.

Over-the-air digital packets are received by a tuner 18 coupled to anantenna 20, and are decoded by a decoder 22. Interaction with a user issupported via a user interface 24, which may include both a displaypanel for displaying information to a user as well as one or morebuttons for receiving input from a user. Audio data packets decoded bydecoder 22 are converted into an analog format by a digital-to-analog(D/A) converter 26, with the analog output of converter 26 fed to anamplifier 28 that drives one or more loudspeakers 30. It will beappreciated that the reception and decoding of digital data packets, thegeneration and emission of an audible signal based upon the informationwithin such packets, and the interaction with a user are all wellunderstood functions implemented by digital radio receivers.

An additional broadcast reception device, e.g., a cellular transceiver32, may also be utilized in receiver 10 to support the reception of anaudio broadcast signal from an alternate source. Cellular transceiver 32permits receiver 10 to communicate over a cellular or other form ofwireless network, and as such incorporates much of the functionality ofa cellular telephone. In some implementations, cellular transceiver 32may be implemented external from receiver 10, e.g., so that an existingcellular device such as a hard-wired automobile cellular telephone or ahandheld cellular telephone, which is regularly used for normal cellularcommunications, may also be used to receive audio broadcasts when notbeing used for normal cellular communications.

Other broadcast reception devices may be incorporated into receiver 10consistent with the invention, e.g., additional digital radio tuners,modems, wired telephone network interfaces, wireless Internettransceivers, etc. Moreover, in some implementations no additionalbroadcast reception device may be used.

FIG. 2 illustrates an exemplary user interface 24, e.g., as may beutilized in a mobile radio receiver for use in cars, trucks and othervehicles. User interface 24 is implemented specifically as a face platecontrol panel including a plurality of buttons 40-48 for use inreceiving user input and a display 50 capable of displaying informationto a user. User interface 24 includes a number of conventional radiobuttons, including tuning buttons 40, volume buttons 42, scan button 44,seek button 46 and channel select buttons 48, the use and configurationof which are well known in the art.

In the illustrated implementation, the channel select buttons 48 arealso utilized as soft-keys to access various menu options displayed ondisplay 50. The current soft-key functions assigned to these buttons arerepresented by labels 52 displayed in proximity with the associatedbuttons 48.

Display 50 may be implemented using any of a number of known displaytechnologies, including, for example, LCD's, LED's, etc. Moreover, itwill be appreciated that a wide variety of alternate user interfaces maybe used in the alternative. For example, display 50 may incorporate atouch screen to permit direct user input to the display. In otherapplications, alternate computer or other electronic device interfacesmay be used, including keyboards, pointing devices, video displays,etc., as appropriate for the particular type of application within whichthe receiver is being used. The invention is therefore not limited tothe particular user interface disclosed herein.

FIG. 3 illustrates a main routine 60 executed by control program 16 ofFIG. 1. Routine 60 begins in block 62 by starting packet receiver andmonitor tasks to perform various background functions for the receiver.In particular, the packet receiver task (described in connection withFIG. 4 below) processes incoming packets from a digital radio broadcastdata stream received by tuner 18 and decoded by decoder 22 (FIG. 1). Themonitor task (described in connection with FIGS. 5 and 6 below)implements automated selection of an alternate source responsive to thedetected signal strength of a digital radio broadcast received from aprimary source.

Returning to FIG. 3, control next passes to block 64 to initiate anevent-driven loop to process events generated by the receiver. One suchevent capable of being passed to routine 60 is a change channel event,which may be generated for example in response to user input to tune toa different channel, to user input requesting a seek or scan function,to user input directed to a stored channel button, etc., and which isdetected in block 66. Other events, the details of which are notrelevant to an understanding of the invention, are handled in aconventional manner as shown in block 68.

In the illustrated implementation, up to three possible alternatesources of an audio broadcast signal are supported for any given audiobroadcast signal. First, an alternate source may be another carrierfrequency, i.e., a different channel on the same or a different radioband (e.g., AM, FM, digital, etc.). The alternate source may be co-ownedwith, or separately owned from, the primary radio station. A separatelyowned radio station might be considered a suitable an alternate source,for example, if the radio station was broadcasting a syndicated programsuch as a talk show or sports broadcast that is provided to multipleradio stations.

Second, an alternate source may be a transmitter accessible via a wiredor wireless telephone network. The transmitted information may be anaudible signal, such that a listener is capable of listening to abroadcast simply by connecting to the transmitter using the cellulartransceiver and amplifying the received information. In the alternative,the transmitted information may be non-audible information such asdigital packets, which could be received and decoded in much the samemanner as a radio broadcast.

Third, an alternate source may be a server accessible over a computernetwork such as the Internet. The transmitted information may conform toany number of known streaming protocols, among other formats. Moreover,the alternate source may be accessible by receiver 10 via a dedicatedreceiver or tuner, or may be accessible via an intermediate InternetService Provider (ISP) or like party that is capable of interfacing thecellular network with the computer network, so that cellular transceiver32 (FIG. 1) is also capable of connecting to a computer network source.

It will be appreciated that any combination of the above alternatesources may be used in different embodiments. Moreover, other forms ofalternate sources of an audio broadcast signal will be apparent to oneof ordinary skill in the art having the benefit of the instantdisclosure.

Returning to FIG. 3, based upon the above alternate source types, and inresponse to a change channel event, block 66 passes control to blocks70-72 to clear several variables associated with the possible types ofalternate sources accessible by the receiver. Block 70 clears a savedfrequency variable that stores an alternate carrier frequency for agiven audio broadcast signal. Block 72 clears a saved phone numberand/or a saved Uniform Resource Locator (URL) representative of anetwork address through which a computer networked source may beaccessed.

Block 74 next performs a channel change operation to control the tunerto tune to a carrier frequency for a selected channel, an operation thatis well understood in the art. Upon completion of block 74, controlreturns to block 64 to process additional events.

FIG. 4 illustrates an exemplary implementation of a packet receiver task80 consistent with the invention. Task 80 begins in block 82 byinitiating an event-driven loop that waits for digital packets from thedecoder, and for each such packet, passes control to a sequence ofblocks 82-92 to handle the received packets in an appropriate manner.Block 94 detects and handles other types of packets (if any) capable ofbeing provided in the audio broadcast signal, but which are not relevantto an understanding of the invention.

Block 84, for example, detects an audio packet, which is the packet typethat includes the audio data representative of the audio broadcastsignal. For each such packet, control passes to block 96 to stage thepacket to be played over the speakers, in a manner well known in theart.

For information packets, which contain display information such asstation call letters, program information, emergency information, etc.,block 86 handles such packets by passing control to block 98 to initiatedisplay of the included information on the display panel.

Blocks 88, 90 and 92 respectively detect three variations of a sourceidentity packet—that is, the source identity information used toidentify an alternate source associated with a particular audiobroadcast signal. Block 88, for example, detects an alternate frequencypacket, and passes control to block 100 to save the alternate frequencyprovided in such a packet in the saved frequency variable. Block 90detects a phone number packet, and passes control to block 102 to savethe telephone number included in such a packet in the saved phone numbervariable. Block 92 detects a URL packet, and passes control to block 104to save the URL included in such a packet in the saved URL variable.

It will be appreciated that other types of packets may be provided in anaudio broadcast signal to identify other types of alternate sources.Moreover, data formats other than packets may be used to transmit sourceidentifying information consistent with the invention.

FIG. 5 illustrates an exemplary implementation of a monitor task 110consistent with the invention. Task 110 begins in block 111 by pausingfor a delay. Block 112 then determines whether the primary audiobroadcast signal received by tuner 18 is “weak”, e.g., whether thesignal strength of the audio broadcast signal falls below a certainthreshold, thus signifying that the reception of the signal is poor. Ifso, control passes to block 114 to determine whether an alternatecarrier frequency exists, i.e., whether a value is stored in the savedfrequency variable. If so, control passes to block 116 to determinewhether the audio broadcast signal provided at the alternate frequencyis stronger than the current signal (e.g., by briefly tuning tuner 18 tothe alternate frequency). If so, control passes to block 118 to tune thetuner to the alternate frequency, thereby automatically selecting thealternate source. Control then returns to block 111 to wait for a nextmonitoring cycle.

Returning to blocks 114 and 116, if either no alternate frequencyexists, or if the signal at the alternate frequency is not stronger thanthe current (primary) signal, control passes to block 120. Also,returning to block 112, if the signal is not determined to be weak,control likewise passes to block 120.

Block 120 determines whether the signal has been altogether lost, e.g.,whether the signal strength has fallen below another threshold that iseven lower than that tested in block 112. If so, control passes to block122. Otherwise, control returns to block 111.

Block 122 next determines whether a phone number and/or URL exists,i.e., whether values are stored in the saved phone number and saved URLvariables. If either or both exist, control passes to call a usealternate source routine 124. Control then returns to block 111.

FIG. 6 illustrates use alternate source routine 124 in greater detail.Routine 124 begins in block 130 by prompting the user to verify whetheran alternate source should be activated. Included within block 130 islisting any and all available alternate sources (e.g., by checking eachof the saved phone number and saved URL variables). FIG. 2, for example,illustrates a suitable prompt on display 50 when both a phone number anda URL are available.

It is to be noted that soft-key functions are supported for selecting“cell phone”, “ISP”, or “cancel” in response to the prompt. As such, inresponse to a user selection of one of the soft-key functions, controlpasses from block 130 to block 132 to decode the returned selection. Ifa “cancel” option is selected, block 132 terminates routine 124 withoutselecting an alternate source. Otherwise, control passes to block 134 todetermine whether “cell phone” was returned. If so, control passes toblock 136 to dial the stored telephone number, and then to block 138 todetermine whether a connection was established.

Returning to block 134, if “cell phone” was not returned (indicating“ISP” was returned), control passes to block 140 to dial an ISPtelephone number (which is typically previously stored in the receiver)to connect the receiver to an ISP for connection to the Internet. Block142 then logs in to the ISP, typically providing a user name andpassword as is well known in the art (also typically stored in thereceiver). Control then passes to block 138 to verify whether asuccessful connection was made. In the alternative, rather than dialingan ISP to connect to the Internet, a persistent Internet connection maybe supported, whereby blocks 140 and 142 may be omitted from routine124.

If a connection cannot be established, block 138 terminates routine 124without selecting an alternate source. In addition, an error message maybe displayed. If, however, a connection is established, control passesto block 144 to begin playback of audio packets from the alternatesource, including any decoding or formatting required to playback theaudio broadcast signal from the alternate source on the receiver'sspeakers. In addition, for an Internet source, a request to access thespecified URL is also forwarded over the computer network to initiatestreaming of the audio broadcast signal.

Control then passes to enter a monitoring loop including blocks 146 and148. Block 146 determines whether a sufficient signal from the primarysource has again been reacquired, e.g., by periodically monitoring thesingle strength for the tuner when tuned to the frequency for theprimary source of the audio broadcast signal. A threshold signalstrength may need to be exceeded for a predetermined amount of time totrigger block 146, although other manners of determining that a signalhas been reacquired may be used in the alternative.

If the primary signal has been reacquired, control passes to block 150to tune the receiver to the primary source, then to block 152 to haltplayback of the audio packets from the alternate source. Next block 154terminates the connection to the alternate source, and routine 124 iscomplete.

Block 148 determines whether the current channel has been changed,indicating that a different audio broadcast signal is to be played backto the user. If so, control passes to block 152 to stop playback of thealternate source, and then to block 154 to terminate the connection tothe alternate source. Routine 124 is then complete.

FIG. 7 illustrates an exemplary digital radio transmission system 200suitable to broadcasting an audio broadcast signal with embedded sourceidentifying information as disclosed herein. System 200 includes adigital audio signal source 202 coupled via a multiplexer 204 to atransmitter 206. Also coupled to multiplexer 204 is alternate sourceidentifying information source 208, and responsive to a select signalgenerated by a controller (not shown), digital packets from one of thedigital audio signal source 202 and the information source 208 is fed tothe transmitter for broadcast on an antenna 210. The controllertypically operates to periodically embed one or more different sourceidentifying packets into the digital data stream represented by thedigital audio broadcast signal output by source 202.

One or more alternate sources for the digital audio signal are shown inFIG. 7, including a second transmitter 212 configured to broadcast thedigital audio signal over a different carrier frequency than transmitter206 (typically via a geographically-dispersed antenna 214), a modem 216configured to interface with compatible receivers over a telephonenetwork 218 (which may include wired and/or wireless telephonenetworks), and a server 220 configured to interface with compatiblereceivers over the Internet 222 or other computer network. Any of theaforementioned alternate sources may be omitted from a digital radiotransmission system consistent with the invention, and one or morealternate sources may be controlled by third parties, rather than beingprovided within an integrated system. Furthermore, it will beappreciated that while each alternate source generally broadcasts thesame audio broadcast signal, the broadcast by each source may be delayedrelative to other sources. Moreover, for the telephone network, ratherthan a modem, a transmitter capable of decoding and generating anaudible signal from the audio broadcast signal may be used, such thatthe actual unencoded audio signal is received by the cellulartransceiver of a compatible receiver.

Various modifications may be made to the illustrated embodiments withoutdeparting from the spirit and scope of the invention. For example, FIG.5 illustrates automated (without prompting) switching between a primarysource and an alternate frequency source, and partially-automated (withprompting) switching between a primary source and a non-radio alternatesource. In other embodiments, however, prompts may selectively be usedor omitted for different types of alternate sources.

Moreover, FIG. 5 illustrates an implementation whereby alternatefrequency sources are prioritized relative to non-radio sources, byvirtue of the separate signal strength thresholds tested by themonitoring task. In other embodiments, however, different relativepriorities may be assigned to different alternate sources, and more thanone alternate source may share the same relative priority.

It will also be appreciated that source switching need not be performedrelative to signal strength determinations. Rather, purely manualselection of alternate sources may be desirable in some embodiments.

Other modifications will become apparent to one of ordinary skill in theart. Therefore, the invention lies in the claims hereinafter appended.

1. A method of receiving an audio broadcast, the method comprising:receiving an audio broadcast signal from a first source; detecting asource identifier in the audio broadcast signal that identifies analternate source for the audio broadcast signal, wherein the alternatesource transmits the audio broadcast signal via a medium other than thatof the first source; and receiving the audio broadcast signal from thealternate source identified by the source identifier.
 2. The method ofclaim 1, wherein receiving the audio broadcast signal from the alternatesource identified by the source identifier is performed using thedetected source identifier.
 3. The method of claim 1, wherein the firstsource comprises a local radio station.
 4. The method of claim 1,wherein the alternate source comprises a local radio station.
 5. Themethod of claim 1, wherein the source identifier comprises a telephonenumber, and wherein receiving the audio broadcast signal from thealternate source comprises: dialing the telephone number on a cellularnetwork; and receiving the audio broadcast signal over the cellularnetwork.
 6. The method of claim 1, wherein the source identifiercomprises a network address identifier that identifies a storagelocation on a computer network that broadcasts the audio broadcastsignal, and wherein receiving the audio broadcast signal from thealternate source comprises connecting to the storage location on thecomputer network to receive the audio broadcast signal.
 7. The method ofclaim 6, wherein the network address identifier comprises a UniformResource Locator (URL), and wherein receiving the audio broadcast signalfrom the alternate source further comprises: dialing a telephone numberof an Internet Service Provider (ISP) on a cellular network; and sendingthe URL to the ISP over the cellular network.
 8. The method of claim 1,further comprising detecting weak reception of the audio broadcastsignal from the first source, wherein receiving the audio broadcastsignal from the alternate source is performed responsive to detectingthe weak reception.
 9. The method of claim 8, wherein detecting weakreception further comprises detecting lost reception of the audiobroadcast signal from the first source, whereby receiving the audiobroadcast signal from the alternate source is performed responsive todetecting the lost reception.
 10. The method of claim 8, furthercomprising: detecting strong reception of the audio broadcast signalfrom the first source during reception of the audio broadcast signalfrom the alternate source; and discontinuing reception of the audiobroadcast signal from the alternate source responsive to detecting thestrong reception.
 11. The method of claim 1, further comprising: playingback the audio broadcast signal received from the first source; andafter detecting the source identifier, discontinuing playback of theaudio broadcast signal from the first source and playing back the audiobroadcast signal from the alternate source identified by the sourceidentifier.
 12. The method of claim 11, wherein discontinuing playbackof the audio broadcast signal from the first source and playing back theaudio broadcast signal from the alternate source identified by thesource identifier is performed automatically.
 13. An apparatus,comprising: a receiver configured to receive an audio broadcast signalfrom a first source; and a controller coupled to the receiver andconfigured to detect a source identifier in the audio broadcast signalthat identifies an alternate source for the audio broadcast signal, thecontroller further configured to initiate reception of the audiobroadcast signal from the alternate source identified by the sourceidentifier, wherein the alternate source transmits the audio broadcastsignal via a medium other than that of the first source.
 14. Theapparatus of claim 13, wherein the controller is configured to receivethe audio broadcast signal from the alternate source identified by thesource identifier using the detected source identifier.
 15. Theapparatus of claim 13, wherein the first source comprises a local radiostation.
 16. The apparatus of claim 13, wherein the alternate sourcecomprises a local radio station.
 17. The apparatus of claim 13, furthercomprising a cellular transceiver coupled to the controller, wherein thesource identifier comprises a telephone number, and wherein thecontroller is configured to initiate reception of the audio broadcastsignal from the alternate source by controlling the cellular transceiverto dial the telephone number on a cellular network, and receiving theaudio broadcast signal over the cellular network.
 18. The apparatus ofclaim 13, wherein the source identifier comprises a network addressidentifier that identifies a storage location on a computer network thatbroadcasts the audio broadcast signal, and wherein the controller isconfigured to initiate reception of the audio broadcast signal from thealternate source by connecting to the storage location on the computernetwork to receive the audio broadcast signal.
 19. The apparatus ofclaim 18, further comprising a cellular transceiver coupled to thecontroller, wherein the network address identifier comprises a UniformResource Locator (URL), and wherein the controller is configured toinitiate reception of the audio broadcast signal from the alternatesource further by dialing a telephone number of an Internet ServiceProvider (ISP) on a cellular network, and sending the URL to the ISPover the cellular network.
 20. The apparatus of claim 13, wherein thecontroller is further configured to detect weak reception of the audiobroadcast signal by the receiver, and to initiate reception of the audiobroadcast signal from the alternate source responsive to detecting theweak reception.
 21. The apparatus of claim 20, wherein the controller isfurther configured to detect strong reception of the audio broadcastsignal from the first source during reception of the audio broadcastsignal from the alternate source, and to discontinue reception of theaudio broadcast signal from the alternate source responsive to detectingthe strong reception.
 22. The apparatus of claim 13, wherein thecontroller is further configured to initiate playback of the audiobroadcast signal received from the first source, and, after detectingthe source identifier, to discontinue playback of the audio broadcastsignal from the first source and initiate playback of the audiobroadcast signal from the alternate source identified by the sourceidentifier.
 23. The apparatus of claim 22, wherein the controller isconfigured to discontinue playback of the audio broadcast signal fromthe first source and initiate playback of the audio broadcast signalfrom the alternate source identified by the source identifierautomatically.
 24. A program product, comprising: a program for acontroller coupled to a receiver capable of receiving an audio broadcastsignal from a first source, the program configured to detect a sourceidentifier in the audio broadcast signal that identifies an alternatesource for the audio broadcast signal, and to initiate reception of theaudio broadcast signal from the alternate source identified by thesource identifier, wherein the alternate source transmits the audiobroadcast signal via a medium other than that of the first source; and asignal bearing medium bearing the program.
 25. A method of transmittingan audio signal, the method comprising: embedding a source identifierwithin an audio signal configured for transmission by a first source,wherein the source identifier identifies an alternate source for theaudio signal, wherein the alternate source transmits the audio broadcastsignal via a medium other than that of the first source; and with thefirst source, broadcasting the audio signal with the source identifierembedded therein.
 26. The method of claim 25, wherein the audio signalcomprises a digital radio data stream, and wherein the source identifiercomprises a packet embedded within the digital radio data stream. 27.The method of claim 25, wherein the source identifier comprises atelephone number, the method further comprising transmitting the audiosignal over a telephone network.
 28. The method of claim 25, wherein thesource identifier comprises a network address identifier that identifiesa storage location on a computer network, the method further comprisingtransmitting the audio signal over the computer network.
 29. The methodof claim 25, wherein the first source comprises a local radio station.30. The method of claim 25, wherein the alternate source comprises alocal radio station.
 31. An apparatus, comprising: a controllerconfigured to embed a source identifier within an audio signal, thesource identifier identifying an alternate source for the audio signal;and a transmitter configured to broadcast the audio signal with thesource identifier embedded therein, wherein the alternate sourcetransmits the audio broadcast signal via a medium other than that of thetransmitter.
 32. The apparatus of claim 31, wherein the transmittercomprises a digital radio transmitter that transmits the audio signal asa digital radio data stream, and wherein the source identifier comprisesa packet embedded within the digital radio data stream.
 33. Theapparatus of claim 31, wherein the source identifier comprises atelephone number, the apparatus further comprising a modem configured totransmit the audio signal over a telephone network.
 34. The apparatus ofclaim 31, wherein the source identifier comprises a network addressidentifier that identifies a storage location on a computer network, theapparatus further comprising a server configured to transmit the audiosignal over the computer network.
 35. The apparatus of claim 31, whereinthe transmitter broadcasts a local radio broadcast signal.
 36. Theapparatus of claim 31, wherein the alternate source comprises a localradio station.
 37. A method of receiving an audio broadcast, the methodcomprising: receiving an audio broadcast signal from a first source;playing back the audio broadcast signal received from the first source;detecting a source identifier in the audio broadcast signal thatidentifies an alternate source for the audio broadcast signal, whereinthe alternate source transmits the audio broadcast signal via adifferent medium from that of the first source; receiving the audiobroadcast signal from the alternate source identified by the sourceidentifier; and discontinuing playback of the audio broadcast signalfrom the first source and playing back the audio broadcast signal fromthe alternate source identified by the source identifier
 38. The methodof claim 37, wherein the first source comprises a local radio station.39. The method of claim 37, wherein the second source comprises a localradio station.